Workers that must perform a task in an environmentally unsafe area, such as Hazmat cleanup or asbestos removal, must wear garments that protect both the worker's skin and respiratory tract. Garments for protecting workers from exposure in toxic or hazardous environments typically include a total encapsulating suit to isolate the worker's body and a hood and breathing mask to isolate the worker's respiratory tract from the toxic agents in the hostile environment. The suits are normally constructed of a fluid impermeable material made from a variety of different plastics. Since the suits are impermeable to fluids, they do not "breathe" (i.e., do not allow air to pass through the suit material). As a result, the interior of the suit becomes quite warm and uncomfortable for the wearer while he is working.
Any encapsulating suit that is impermeable to a fluid, must be worn with some type of respiratory air supply. The respiratory air supply can be either self-contained or externally provided by an airline to a breathing mask inside of the suit. A suit and breathing mask using an external respiratory air supply is shown in the MSA brochure entitled "Constant, Flow or Pressure Demand Duo-Flo and Duo-Twin Respirators" (10-01-14).
Often, these encapsulating suits will also use an external air supply to provide air circulation to the interior of the suit and thereby provide cooling to the suit and the worker. U.S. Pat. Nos. 3,777,750; 4,271,833 and 4,458,680 are examples of such suits. In suits such as these, the cooling air provided to the interior of the suit is also used for breathing by the worker since no separate air supply is provided. The disadvantage with this arrangement, however, is that the worker is breathing a mixture of used air (i.e., exhaled air containing CO.sub.2) and fresh air (from the air supply) in the suit rather than breathing clean fresh air directly from the air supply.
To overcome this disadvantage, some suits that provide respiratory air by an airline, such as those used in the asbestos removal industry, are normally cooled by a separate airline that blows cooling air directly into the interior of the suit. As a result, the worker does not breathe the cooling air. These suits, however, must be connected to two separate airlines, one that supplies breathing air at a given volume and pressure to the breathing mask and the other one that supplies cooling air at a different volume and pressure to the interior of the suit.
Since the suit is connected to two separate airlines, the worker's mobility and dexterity is greatly limited. The weight of the suit is also dramatically increased by the addition of the second airline. As a result, the worker must contend with reduced movement as well as excess weight while already performing tasks in an uncomfortable and hazardous environment.
The worker is further limited in his ability to enter or exit the work environment due to the weight and constrictions of the two airlines. Because of these added restrictions placed on the worker, the worker's productive time inside the hostile work environment is reduced. Additionally, the necessity for two airlines can be dangerous to workers who must be able to climb or run in making a quick escape from a hazardous area.
There is a need, therefor, for a totally encapsulating suit which has a cooling device that both supplies respiratory air directly to the worker through his breathing mask and also supplies cooling air to the interior of the suit while requiring only a single airline from an external air supply. By using a single airline from one external air supply, the worker's mobility is greatly increased and the stress and fatigue associated with transporting the extra weight of a second airline is eliminated.